This invention relates to a precision metering device of the type having a bucket or series of buckets gravitationally discharging fluent materials into a collector and, more particularly, to a dispenser for fluent materials such as grains and seeds, fertilizers, herbicides, insecticides, inoculants, and other granular materials, especially for use in conjunction with a planter, incorporating the precision metering device and its novel bucket.
Oftentimes, in planting rows of seeds, such as corn, in a field, it is desirable to apply herbicides, insecticides, and fertilizers at the same time. Granular chemical distributors which have been used for this purpose generally have a hopper with a rotating trap chamber at the bottom. These devices are commonly mounted along the row trailing the planter devices and discharge by gravity through a distributor to lay a banded pattern. This was acceptable for planting a few rows. However, as the amount of rows being planted increased, for example to the sixteen row planters being sold today, it was still necessary to provide a hopper and trap chamber distributor for each type of chemical and for each row thereby greatly increasing the time necessary to fill the planter with chemicals for each row. Moreover, if the rate of discharge was to be adjusted, the adjustment had to be made at each distributor and increased the possibility of having nonuniform amounts of material being deposited in the various rows.
In the planting art, the Loesch et al. U.S. Pat. No. 3,637,108, and the Bauman et al. U.S. Pat. No. 3,860,146, teach a pneumatic planter, now embodied in the International Harvester Company CYCLO.RTM. planter, in which the seed is stored in a central hopper feeding into a pressurized perforated drum which carries the seed in the perforations up over a manifold collector whereat the perforations are closed off and the seed drops into the collector manifold for transport by air through tubes to each row. The farmer then had only one large hopper to fill with seed for distribution to as many as eight rows. However, for granular chemicals, he still had to fill the hopper at each row.
Other problems with the trap chamber dispensers are that the metering devices require an orifice or a positive displacement element with close tolerances, the individual units can become out of adjustment between rows, the material in the hopper can bridge the metering element or become lumpy, and that individual metering devices are required for each row. Further, granular materials can cause abrasive wear which may yield metering inaccuracies.
The Smith et al. U.S. Pat. No. 3,093,268 teaches a pneumatic fertilizer distributor having a metering device similar in some respects to that described and claimed herein. However, the Smith metering system does not have a axially divided collector which feeds individual rows but rather a single collector from which the fertilizer is blown into a discharge tube which apparently lays a single elongated band of material. Further, Smith teaches a rotating housing, which carries all of the fertilizer supply, having buckets mounted on its internal periphery. The rotating housing tends to make sealing difficult and carrying the entire fertilizer supply both limits the capacity and increases the power necessary to drive the device. Finally, the buckets described do not dump the material at a substantially uniform rate per degree of rotor rotation, which is a primary feature of the apparatus described herein and helps produce an even distribution of the material along the row.